The universal serial bus (USB) provides a low cost solution for attaching peripheral devices to a host device, such as a host computer (e.g., personal computer such as a laptop or desktop or other host), so that the peripheral devices and the host device can communicate with each other. A compound device is a device that includes an internal USB hub and is able to connect a host device connected to an upstream port with one or more peripheral devices connected to downstream ports. The peripheral devices may include devices such as printers, scanners, keyboards, a mouse, digital cameras, digital video cameras, data acquisition devices, modems, speakers, telephones or video phones, storage devices such as ZIP drives, or other peripherals or devices. In addition, the compound device can include a mass storage device, such as an internal hard disk drive.
When the mass storage device is part of a compound device—internally connected downstream of the USB hub—the upstream port of the compound device is not capable of manual control by the user. That is, the encryption state of the mass storage may not reflect what is intended by the user when the host device is plugged into or unplugged from the upstream port of the compound device.
The system describes one aspect of an apparatus configured to implement a security state for preventing access to a storage device, including a communications hub including an upstream port and a plurality of downstream ports. A first downstream port of the plurality of downstream ports is connected to the storage device, and one or more other downstream ports of the plurality of downstream ports are configured to connect to one or more external devices. The apparatus includes one or more processors configured to monitor the upstream port, determine a connection state of the upstream port, and implement the security state for preventing access to the storage device based on the determined connection state.